A new study in mice suggests that a way of starving tumors of their blood supply may cause heart attacks and strokes. This study raises concerns about this type of cancer therapy according to the researchers at UCLA.Drugs that block blood vessel growth, such as Avastin, do so from the outside of the cell by blocking vascular endothelial growth factor (VEGF), a signaling protein.
In the study, Luisa Irula-Arispe and her team bred mice that lacked VEGF in endothelial cells. The team did not use drugs to block the VEGF. More than half of the mice in their study suffered heart attacks and fatal strokes and even those that lived became ill. Irula-Arispe said that signaling inside the cell is different that signaling outside the cell. She said it is not clear if such drugs as Avastin are dangerous., although she believes that researchers should try to find a more targeted way of getting the drug to the tumor. Currently Avastin and other such drugs are infused, and therefore circulate through the patient's whole body.











1. The fact that proving efficacy and toxicity in one situation does nothing to prove efficacy and toxicity in any other situation. Both the mechanism and the subjects were different. It's hard to tell a doctor (and patient) to ratchet back on the anti-VEGF drug they're using when the disease setting is stage IV lung, ovarian or pancreatic cancer.
In "curable" diseases, therapy-related, late onset sequelae are becoming a real problem. Many of these new "targeted" therapies often get a pass on toxicities because they are just so darn cool (Herceptin and CHF in the adjuvant setting is another example).
This is perhaps why Herceptin causes heart problems. Among other things, it's an antiangiogenic. Any cancer drug may lead to serious health problems in the long term. You have to remember that all drugs, including aspirin, digoxin (Foxglove), morphine and oxycontin can and do have lethal side effects. Lots of people have died from penicillan. It's all risk/benefit ratio.
The problem is that few drugs work the way oncologists think and few of them take the time to think through what it is they are using them for.
Posted at 7:59PM on Aug 29th 2007 by Gregory D. Pawelski